We investigate the scattered palindromic subwords in a finite word. We start by characterizing the words with the least number of scattered palindromic subwords. Then, we give an upper bound for the total number of palindromic subwords in a word of length $n$ in terms of Fibonacci number $F_n$ by proving that at most $F_n$ new scattered palindromic subwords can be created on the concatenation of a letter to a word of length $n-1$. We propose a conjecture on the maximum number of scattered palindromic subwords in a word of length $n$ with $q$ distinct letters. We support the conjecture by showing its validity for words where $q\geq \frac{n}{2}$.
翻译:我们用一个限定的字来调查分散的低温亚字。 我们首先用最少的分散的低温亚字来描述单词的特性。 然后, 我们用一个长度的字, 给低温亚字的总数设定一个上限。 以Fibonacci number $F_ $F_ n 来证明, 最多能用一字的长度 $- 1 来将新的分散的低温亚字拼成一个长度 $- 1 美元 的字母。 我们建议用一个长度的字, $ $ $ 美元, 对分散的低温亚字的最多数量进行一个猜测。 我们通过用 $qqqqqqqqq \ frac{ n2} 的字来显示其有效性来支持这些推测 。